Stator element for a holweck pump stage, vacuum pump having a holweck pump stage and method of manufacturing a stator element for a holweck pump stage

Abstract

A stator element for a Holweck pump stage has a base shape of substantially cylinder jacket shape or a kit of parts for a stator element for a Holweck pump stage which has a base shape of a substantially cylinder jacket shape, wherein the stator element or the kit of parts comprises a plurality of stator parts which are separate from one another, which are assembled to form the stator element or can be assembled to form the stator element. A vacuum pump having a Holweck pump stage as well as to a method of manufacturing a stator element for a Holweck pump stage or of manufacturing a kit of parts for a stator element for a Holweck pump stage are also disclosed.

What is claimed is: 
     
       1. A stator element for a Holweck pump stage which has a base shape of substantially cylinder jacket shape, wherein the stator element comprises a plurality of mutually separate stator parts ( 12 ,  12 ′,  12 ″) which are assembled to form the stator element or which can be assembled to form the stator element, and wherein each of the plurality of separate stator parts ( 12 ,  12 ′,  12 ″) only covers a part region of a peripheral angle of the stator element defined relative to a longitudinal axis ( 24 ) of the stator element, and each of the separate stator parts ( 12 ,  12 ′,  12 ″) has a plurality of web sections ( 14 ,  14 ′,  14 ″),
 wherein a surface of the stator element provided with pump activity is divided by two mutually adjacent stator parts ( 12 ,  12 ′ and  12 ″) parallel to the longitudinal axis ( 24 ) of the stator element and/or obliquely to the longitudinal axis of the stator element, the two mutually adjacent stator parts ( 12 ,  12 ′,  12 ″) have mutually disposed and facing each other separating surfaces ( 18 ,  20 ,  22 ) extending through the surface of the stator element. 
 
     
     
       2. The stator element in accordance with  claim 1 , wherein at an outer jacket surface and an inner jacket surface of each stator part forms a surface provided with pump activity, and the plurality of web sections is provided on both the outer and inner jacket surfaces, extend helically in an axial direction and have grooves ( 16 ) arranged between the web sections ( 14 ,  14 ′,  14 ″), the grooves extending helically in an axial direction, and wherein the stator parts ( 12 ,  12 ′,  12 ″) each forming one of a region of the surface provided with pump activity and the surfaces provided with pump activity. 
     
     
       3. The stator element in accordance with  claim 1 , wherein each stator part ( 12 ,  12 ′,  12 ″) covers a range of less than or equal to 180° of the peripheral angle of the stator element defined relative to a longitudinal axis ( 24 ) of the stator element. 
     
     
       4. The stator element in accordance with  claim 1 , wherein at least one section of a surface of the stator element provided with pump activity is divided by two mutually adjacent stator parts ( 12 ,  12 ′,  12 ″) along one of a groove ( 16 ) and a web ( 14 ,  14 ′,  14 ″) of the surface provided with pump activity. 
     
     
       5. The stator element in accordance with  claim 1 , wherein each stator part ( 12 ,  12 ′,  12 ″) is configured such that a plurality of stator parts ( 12 ,  12 ′,  12 ″) identical to the stator part ( 12 ,  12 ′,  12 ″) can be assembled to form the stator element. 
     
     
       6. The stator element in accordance with  claim 1 , wherein the stator element is assembled from a kit of parts which comprises the plurality of mutually separate stator parts ( 12 ,  12 ′,  12 ″) which can be assembled to form the stator element. 
     
     
       7. A method of manufacturing a stator element for a Holweck pump stage which has a base shape of substantially cylinder jacket shape, the method comprising the steps of
 manufacturing a plurality of separate stator parts ( 12 ,  12 ′,  12 ″) which form together a stator element, with each stator part having a plurality of web sections ( 14 ,  14 ′,  14 ″), and 
 assembling the stator parts ( 12 ,  12 ′,  12 ″) from a kit of stator parts to form the stator element, so that each of the plurality of stator parts only covers a part region of a peripheral angle of the stator element defined relative to a longitudinal axis of the stator element, 
 wherein assembling of the stator element is so carried out that a surface of the stator element provided with pump activity is divided by two mutually adjacent stator parts ( 12 ,  12 ′ and  12 ″) parallel to the longitudinal axis ( 24 ) of the stator element and/or obliquely to the longitudinal axis of the stator element, with mutually disposed and facing surfaces ( 18 ,  20 ,  22 ) of the two mutually adjacent stator parts ( 12 ,  12 ′,  12 ″) extending through the surface of the stator element. 
 
     
     
       8. The method in accordance with  claim 7 , further comprising the step of
 first manufacturing a base body for the stator part ( 12 ,  12 ′,  12 ″), and subsequently post-machining the base body to form the stator part ( 12 ,  12 ′,  12 ″). 
 
     
     
       9. The method in accordance with  claim 8 , wherein the step of manufacturing the base body is carried out by a primary molding process. 
     
     
       10. The method in accordance with  claim 8 , wherein the step of post-machining the base body is carried out by a shaping process. 
     
     
       11. The method in accordance with  claim 7 , wherein the step of
 manufacturing the plurality of stator parts ( 12 ,  12 ′,  12 ″) comprises the step of manufacturing each stator part ( 12 ,  12 ′,  12 ′) by molding. 
 
     
     
       12. The method in accordance with  claim 7 , wherein the each stator part ( 12 ,  12 ′,  12 ″) is manufactured from a plastic at least in part. 
     
     
       13. The method in accordance with  claim 7 , wherein the step of manufacturing the each stator part ( 12 ,  12 ′,  12 ″) comprises the step of manufacturing the stator part ( 12 ,  12 ′,  12 ″) by blow molding or by three-dimensional printing. 
     
     
       14. A method according to  claim 7 , comprising the step of manufacturing at least one member selected from the group comprising the stator element with the plurality of stator parts ( 12 ,  12 ′,  12 ″), a base body for the stator element and a base body for each stator part ( 12 ,  12 ′,  12 ″) by one of the following processes selected from the group comprising molding manufacturing from a plastic at least in part by blow molding and by three-dimensional printing so that each of the plurality of stator parts only covers a part region of a peripheral angle of the stator element defined relative to a longitudinal axis ( 24 ) of the stator element. 
     
     
       15. A vacuum pump, having at least one Holweck pump stage which comprises at least one stator element, the stator element having a base shape of substantially cylinder jacket shape, and with the stator element comprising a plurality of mutually separate stator parts ( 12 ,  12 ′,  12 ″) with each of the plurality of stator parts having a plurality of web sections ( 14 ,  14 ′  14 ″) which are assembled to form the stator element or which can be assembled to form the stator element so that each of the plurality of the stator parts only covers a part region of a peripheral angle of the stator element relative to a longitudinal axis ( 24 ) of the stator element,
 wherein a surface of the stator element provided with pump activity is divided by two mutually adjacent stator parts ( 12 ,  12 ′ and  12 ″) parallel to the longitudinal axis ( 24 ) of the stator element and/or obliquely to the longitudinal axis of the stator element, the two mutually adjacent stator parts ( 12 ,  12 ′,  12 ″) have mutually disposed and facing each other separating surfaces ( 18 ,  20 ,  22 ) extending through the surface of the stator element.